Hydrogenation in presence of raney nickel



Patented Mar. 30, 1954 HYDROGENATION IN PRESENCE OF RANE Y NICKEL Thomas B. Steadman, W ban, Mass assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York No Drawing. Application July 18, 1951, Serial No. 237,485

3 Claims. 1

This invention relates to hydrogenation and more specifically pertains to an improved process of hydrogenation in the presence of Raney nickel by the use of a surface-active agent.

For a long tim Raney nickel has been invaluable as a hydrogenation catalyst in the industrial applications of hydrogenation. Because of the somewhat involved preparation of this catalyst, it is the practice to prepare the catalyst in large batches and store it under an inert liquid until required for use. It had been found that when Raney nickel catalyst is stored under water, the catalyst retains its activity quite satisfactorily. However, when the catalyst is removed from the water and used, especially when used to catalyze the hydrogenation of water-immiscible materials containing carbon-to-carbon unsaturation, the catalyst does not disperse satisfactorily in the material to be hydrogenated and substantially longer reaction times are required than is desirable.

I have discovered that the hydrogenation using Raney nickel, either as freshly prepared or after bein stored under water, of water-immiscible materials can be materially speeded up by adding an extremely small quantity of a surfaceactive agent to the water-immiscible material. An amount of surface-active agent as small as 0.1% to 5% by weight of the Raney nickel catalyst is sufficient to decrease the reaction time by one half or more.

The process of this invention can be employed to hydrogenate such liquid materials as the unsaturated animal and vegetable oils and fats; olefinic compounds, straight-chained compounds containing one or more double bonds or triple aonds; aromatic compounds, compounds containin benzene rings, unsaturated heterocyclic compounds; the higher aldehydes and ketones (to the corresponding hydroxy compounds); nitrile (to amines), and the lik and. many other waterimmiscible organic materials.

The surface-active or wetting agents which are suitable for the process of this invention include those typified by the following general classifications: sodium and potassium salts of fatty acids known as soft and hard soaps; fatty acids saponified with amines and amino alcohols; watersoluble salts of disproportionated abietic acid known as rosin soaps; water-soluble salts of the hydroxy aldehyde acids present in seaweeds known as algin soaps; water-soluble alkali-casein compositions; water-soluble lignin sulfonate salts; water-soluble long-chain alcohols usually ccntaining'lo to 18 carbon atoms; water-soluble salts of sulfated fatty alcohols containing 10 to 18 carbon atoms; water-soluble salts of fatty acid amides; water-soluble salts of .sulfated esters of fatty acids; water-soluble alkyl sulfonates having about 8 to 20 carbon atoms in the alkyl group; water-soluble aryl sulfonates; Water-soluble alkyl aryl sulfonates; Water-soluble aralkyl sulfonates; water-soluble sorbitan monolaurates, palmitates, -stearates, and -o1eates, quaternary alkyl halides, and others. These wetting or surface-active agents are sold under numerous trade names and may be either pure compounds or mixtures of compounds of the same general group.

In general, as hereinbefore stated, the wetting or surface-active agents are employed in rather small quantities being in the range at 0.1% to 5.0% by Weight of the Raney nickel catalyst. It will be readily understood that the optimum quantity of the wetting or surface-active agent employed will of necessity vary from class to class as well as among members of the same class according to the wetting efiiciency of the specific material employed. In any case 0.1% to 5% by weight of the wetting agent based on the Raney nickel catalyst will be sufiicient.

The following specific example will illustrate th process of this invention.

Example I Fifty-six parts by weight of 2,4-dimethy1-5,6- dihydro-1,2-pyran, 20 parts by weight of Raney nickel which had been stored under water and 0.2 part by weight of sodium lauryl sulfate as the wetting agent were charged into a Burgess-Parr hydrogenator. Hydrogen was charged into the hydrogenator. After seven hours at room temperature, the absorption of hydrogen was complete.

The following example illustrates the hydrogenation of the same compound at room temperature, in the absence of a Wetting or dispersing agent.

Example II Fifty-six parts by weight of 2,4-dimethyl-5,6- dihydro-1,2-pyran and 20 parts by weight of the same Raney nickel used in Example I were charged into a Burgess-Parr hydrogenator. Hydrogen was charged into the hydrogenator. This hydrogenation was also conducted at room temperature, but complete hydrogenation required 16 hours.

A comparison of the reaction time-required for the hydrogenation of 2,4-dimethyl-5,6-dihydro- 1,2-pyran with the wetting agent present (Example I) and the reaction time required when no wetting agent was present (Example II) illustrates the unusual results obtainable by the process of this invention. Substantially equivalent results, a reduction of reaction time by more than 50%, are obtainable by the use of a wetting agent with any of the water-immiscible materials of the classes hereinbefore enumerated. While I have illustrated my invention by means of a specific example, I do not thereby desire or intend to limit myself solely thereto, for as hitherto stated, the precise proportions of the reactants can be varied and other members of the classes of wetting agents and the classes of water-immiscible materials can be employed in this hydrogenation process without departing from the spirit and scope of my invention as defined in the appended claims.

I claim: 1. A method of hydrogenating water-immis cible, organic compounds which comprises reacting said compounds with hydro en under reducing conditions in the presence of a Raney nickel catalyst which has been previously stored under water, said catalyst being associated during such 4 storage with from about 0.1% to about 5% by weight, based on the weight or the catalyst of a wetting agent.

2. A method of hydrogenating water-immiscible, organic compounds which comprises reacting said compounds with hydrogen under reducing conditions in the presence of a Raney nickel catalyst which has been previously stored under water, said catalyst being associated during such storage with from about 0.1% to about 5% by weight, based on the weight of the catalyst of sodium lauryl sulfate.

3. The method of claim 2 in which the wetting agent is added to the aqueous storing medium in a quantity of about 1% by weight of the catalyst.

THOMAS R. STEADMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,994,058 Wietzel et al Mar. 12, 1935 2,440,929 Bremner et a1. May 4, 1948 2,546,019 Smith Mar. 20, 1951 

1. A METHOD OF HYDROGENATING WATER-IMMISCIBLE, ORGANIC COMPOUNDS WHICH COMPRISES REACTING SAID COMPOUNDS WITH HYDROGEN UNDER REDUCING CONDITIONS IN THE PRESENCE OF A RANEY NICKEL CATALYST WHICH HAS BEEN PREVIOUSLY STORED UNDER WATER, SAID CATALYST BEING ASSOCIATED DURING SUCH STORAGE WITH FROM ABOUT 0.1% TO ABOUT 5% BY WEIGHT, BASED ON THE WEIGHT OF THE CATALYST OF A WETTING AGENT. 